If you have a machine with CPUs faster than 419MHz, you can't boot from
the 2.5.1 or 2.6 CDROM media.

Instead, your machine comes with an Environmental Operating CD. Boot
from that, and then you have the option of installing 2.5.1 or 2.6.
When you select 2.6, you'll be able to insert the 2.6 CDROM and
continue.

Original posting : -

> Hello Managers,
>
> I'm using a sun ultra 80 which has an internal CDROM unit, it
> currently has Solaris 7 installed. I want to downgrade it from Solaris 7
to
> Solaris 2.6
> When i have tried to boot from the cdrom(Solaris 2.6) using 'boot cdrom'
at
> the 'ok'
> prompt, i have obtained boot error messages,
>
> Any idea why my sun ultra 80 does not booting cdrom??